Diet may affect child development, and by completely different mechanisms, the risk of several chronic diseases, but additional research is needed. This report will focus on my study of diet in relation to risk of amyotrophic lateral sclerosis (ALS). Other work in this area is reflected by my list of publications. Defects in antioxidant defenses (e.g., superoxide dismutase 1) are a cause of ALS, thus it is reasonable to suspect that antioxidant intake may also affect the incidence or progression of this disease. Results from case-control studies addressing this question, however, have been mixed. Furthermore, case-control data suggest that intake of fat, fiber, and of glutamate may alter risk. My project is an add-on to a large cohort study underway at the National Cancer Institute. The cohort consists of members of the American Association of Retired Persons (AARP) who have completed a dietary questionnaire (approximately 600,000 people). We expect about 150 cases of amyotrophic lateral sclerosis to develop in this cohort by 2004. Large, prospective studies of diet and ALS have not been done and are sorely needed. The AARP cohort was designed to look at diet and other lifestyle factors and cancer, but information on other causes of death is collected. This is an exciting opportunity to focus on non-cancer chronic diseases that are of interest to NIEHS. As a first step, and to follow-up on some of my previous work, I am venturing into the initial stages of a collaboration. Even if the hypotheses noted above turn out to be null, we will have built a bridge that can lead to excellent work on other non-cancer chronic diseases. Last year's progress: Waiting for cases of ALS to accrue has been the major activity. We began negotiations with NCI about how to verify cases of ALS, using medical records.